1. Field of the Invention
The present invention relates to a driving apparatus, and more particularly, to a driving apparatus for driving a liquid crystal display panel.
2. Description of the Prior Art
Because the liquid crystal display (LCD) has advantages of thin appearance, low power consumption, and low radiation, the liquid crystal display has been widely applied in various electronic products for panel displaying. The operation of a liquid crystal display is featured by varying voltage drops between opposite sides of a liquid crystal layer for twisting the angles of the liquid crystal molecules in the liquid crystal layer so that the transparency of the liquid crystal layer can be controlled for illustrating images with the aid of the light source provided by a backlight module. In general, the liquid crystal display comprises a driving apparatus and a liquid crystal display panel. The driving apparatus is employed to provide a plurality of data signals to the liquid crystal display panel based on an image signal, a horizontal synchronization signal, a vertical synchronization signal, a data enable signal and a clock signal.
Along with the demands of high color depth, high resolution and high frame rate in advanced liquid crystal displays under developing, the working frequency regarding an image display operation is required to be much higher. However, in the operation of a prior-art driving apparatus, the signal qualities of the differential signals received by a plurality of source driving circuits are relatively low and quite non-uniform. Since the source driving circuit receiving the worst differential signal is also required to work properly, the working frequency regarding signal transmission must be lowered, and therefore the prior-art driving apparatus is not suitable for a high-frequency operation. In other words, the differential signals having low signal quality are not suitable for high-frequency signal transmission. For instance, regarding a period jitter range of 200 pico-seconds, a driving apparatus may still work properly based on a working frequency of 100 MHz. However, based on a working frequency of 1 GHz, the 1 GHz-based transmission interface of a driving apparatus is then unable to receive the differential signals properly. That is, if the differential signal having low signal quality is transmitted under high working frequency, the noise tolerance will decrease significantly, and therefore voltage-level misjudgments of the differential signal are likely to occur in that the source driving circuit is hard to identify different voltage levels of the differential signal received or even hard to single out each data bit of the differential signal.